The Potential of Biosurfactants in Enhancing Microbiological Oil Degradation in North Sea Seawater

An international team of researchers from the universities of Stuttgart and Tübingen, in collaboration with the China West Normal University and the University of Georgia, has conducted a study to investigate whether biosurfactants can enhance the microbiological degradation of oil in North Sea seawater. The results of this study reveal the potential for a more effective and environmentally friendly approach to oil spill response. The findings have been published in the journal ACS ES&T Water.

The Environmental Impact of Oil Leaks

Oil leaks into the world’s oceans are estimated to reach approximately 1,500 million liters annually. This contributes to significant global environmental pollution, as oil contains hazardous compounds like polycyclic aromatic hydrocarbons that can have toxic or mutagenic effects on organisms. Oil spills, particularly catastrophic incidents involving the rapid release of large quantities of oil into the oceans, such as tanker accidents or incidents at oil drilling platforms, have devastating consequences.

The Role of Chemical Dispersants

In response to oil spill incidents, large amounts of chemical dispersants are routinely applied to dissolve oil slicks, prevent oil from reaching coastlines, and enhance oil dispersion in the water. It is hoped that this will enhance microbial oil degradation. Certain microorganisms naturally present in nature can feed on crude oil components and break them down into harmless substances, thereby naturally cleaning oil-contaminated areas.

However, a study conducted in the United States in 2015 revealed that chemical dispersants in deep-sea water from the Gulf of Mexico can actually slow down microbial oil degradation. This finding led to controversial discussions and a lack of consensus on how to effectively combat oil spills.

The Potential of Biosurfactants

In the search for more environmentally friendly methods to address oil spills, biosurfactants have emerged as a promising alternative to chemical dispersants. Biosurfactants are produced by microorganisms and can increase the bioavailability of oil components, thereby enhancing microbial oil degradation, which is crucial for purification.

To investigate the effects of biosurfactants compared to chemical dispersants, an international research team led by environmental microbiologist Professor Sara Kleindienst, alongside geomicrobiologist Professor Andreas Kappler and biogeochemist Professor Samantha Joye, conducted experiments in a laboratory at the University of Tübingen. They simulated oil spill conditions using over 100 liters of surface water from the North Sea near the island of Helgoland.

The seawater was treated with either the biosurfactant rhamnolipid or a dispersant (Corexit 9500 or Slickgone NS), with and without the presence of oil. The researchers utilized radioactive markers to track the degradation of the oil by microorganisms in detail.

Promising Results

The research team found that the oil microcosms treated with rhamnolipid, the biosurfactant, exhibited the highest rates of microbial hydrocarbon oxidation and protein synthesis. This indicates that the use of biosurfactants can enhance the degradation of oil by microorganisms.

Furthermore, the composition of microbial communities differed significantly between the approaches using biosurfactants and chemical dispersants. This suggests that the use of biosurfactants may stimulate different microbial oil degraders, impacting both their growth and activity. These findings have implications for the cleanup process following oil spills.

The Way Forward

The research team concludes that biosurfactants have great potential for use in future oil spills in the North Sea and similar nutrient-rich ocean habitats. They propose the development of products based on biosurfactants that offer effective and environmentally friendly approaches to combating oil spills. This visionary approach could revolutionize oil spill response and lead to a more sustainable and efficient cleanup process.

In summary, the study highlights the potential of biosurfactants in enhancing microbiological oil degradation in North Sea seawater. By utilizing biosurfactants instead of chemical dispersants, the cleanup process following oil spills can be more effective and environmentally friendly. The research team’s findings pave the way for further exploration and development of biosurfactant-based products to combat oil spills in the future.